I've found a few aggressive fitments on here such as:
Front: 20x9.5 +6 (+1 with 5mm spacer)
Rear: 20x10.5 -12
Yokohama S-Drives 225/35 and 255/35. They run a little wider than other brands.
http://www.the370z.com/wheels-tires/...ml#post2315181
I think it might work just fine with a 245/30/ front tire and my plan of 285 or 275 in the rear. Rear specs are 20x11 +15 but I do still have my 20 and 25mm spacers to play with to match the front's stance if needed.